Bump k8s.io/client-go in /test/custom-task-ctrls/wait-task-beta

Bumps [k8s.io/client-go](https://github.com/kubernetes/client-go) from 0.27.14 to 0.27.15.
- [Changelog](https://github.com/kubernetes/client-go/blob/master/CHANGELOG.md)
- [Commits](kubernetes/client-go@v0.27.14...v0.27.15)

---
updated-dependencies:
- dependency-name: k8s.io/client-go
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

test/custom-task-ctrls/wait-task-beta/go.mod

@@ -6,9 +6,9 @@ require (
 	github.com/emicklei/go-restful v2.16.0+incompatible // indirect
 	github.com/google/go-cmp v0.6.0
 	github.com/tektoncd/pipeline v0.53.1
-	k8s.io/api v0.27.14
-	k8s.io/apimachinery v0.27.14
-	k8s.io/client-go v0.27.14
+	k8s.io/api v0.27.15
+	k8s.io/apimachinery v0.27.15
+	k8s.io/client-go v0.27.15
 	k8s.io/utils v0.0.0-20230505201702-9f6742963106
 	knative.dev/pkg v0.0.0-20231011193800-bd99f2f98be7
 )